Protestors rally outside of the state Capitol during Michigan Gov. Rick Snyder's State of the State address on Tuesday, Jan. 19, 2016, in Lansing, Mich. With the water crisis gripping Flint threatening to overshadow nearly everything else he has accomplished, the Republican governor again pledged a fix Tuesday night during his annual State of the State speech. (Sean Proctor/The Flint Journal-MLive.com via AP)

WASHINGTON (AP) — Michigan should have required the city of Flint to treat its water for corrosion-causing elements after elevated lead levels were first discovered in the city’s water a year ago, the state’s top environmental regulator says in congressional testimony.

State officials “relied on technical compliance (with the law) instead of assuring safe drinking water,” says Keith Creagh, director of the Michigan Department of Environmental Quality. He calls that a mistake.

But state officials are not the only ones who made mistakes in Flint, Creagh says. All levels of government deserve blame in the Flint crisis, he says.

City officials did not follow proper protocol in conducting lead sampling of homes, Creagh says, and the U.S. Environmental Protection Agency “did not display the sense of urgency that the situation demanded.” The Associated Press obtained a copy of Creagh’s testimony in advance of Wednesday’s hearing before the House Oversight and Government Reform Committee.

The hearing is the first on Capitol Hill since the lead contamination crisis in Flint made national news last year.

Flint switched its water source from Detroit’s water system to the Flint River in 2014 to save money while under state financial management. The river water was not treated properly and lead from pipes leached into Flint homes.

Creagh and Joel Beauvais, acting chief of the EPA’s water office, are among those scheduled to testify Wednesday before the House Oversight and Government Reform Committee.

Testimony is likely to focus on a June 2015 memo by an employee in EPA’s Midwest regional office that outlined problems with Flint’s water. The memo was not formally delivered to state environmental officials until November — after the state had begun taking actions to address the lead problem, Creagh said.

“Legitimate concerns raised by EPA’s own expert staff were not elevated or provided to either the city or the state for review and action until after the state’s response was well underway,” Creagh said.

While immediate treatment of the water was not required after lead was first discovered in January 2015, “corrosion treatment should have been required by the MDEQ,” said Creagh, who took over as head of the state agency last month following the resignation of Dan Wyant.

Detroit schools emergency manager Darnell Earley, who was state-appointed emergency manager for Flint when its water source was switched, had been asked to testify at Wednesday’s hearing but declined. The oversight committee issued a subpoena to Earley on Tuesday, but his lawyer refused service, a committee staffer said.

The oversight hearing comes as the FBI said it is working with a multi-agency team investigating the lead contamination in Flint.

FBI spokeswoman Jill Washburn told the AP in an email that the agency is “investigating the matter to determine if there have been any federal violations.” She declined to say when the FBI got involved.

Several local, state and federal officials have resigned since doctors revealed last year that using the Flint River for the city’s drinking water supply caused elevated levels of lead in some children’s blood. Lead contamination has been linked to learning disabilities and other problems. Michigan’s governor has apologized repeatedly for the state’s role.

In addition to the FBI and the EPA, the federal team includes the U.S. Postal Inspection Service, said Gina Balaya, a U.S. attorney’s spokeswoman in Detroit.

In November, the EPA announced it was auditing how Michigan enforces drinking water rules and said it would identify how to strengthen state oversight. The U.S. attorney’s office in Detroit said in January that it was investigating the water crisis with the EPA.

An independent panel appointed by Michigan Gov. Rick Snyder has determined that the state Department of Environmental Quality was primarily responsible for the water contamination. The Michigan Civil Rights Commission also plans to hold hearings to explore whether the civil rights of Flint residents were violated.

On Tuesday, Flint Mayor Karen Weaver told reporters she wants lead pipes removed from the city’s water distribution system as soon as possible. Weaver proposed starting the pipe-removal process at the “highest-risk homes of kids under 6 and pregnant women.”